Only 20% rudder input gives100% output??

[gadget463]

Hey all wondering if anyone can help me fix this little problem. I almost have my 1st real heli together, a Trex 450SA. I am using a S9650 for the tail servo with a Logictech 2100T gryo and a DX7 transmitter and AR7000 reciever. (and HS65MG's but I don't think those matter here). Before I try to fly it I notice that the rudder only requires at MOST 20% stick input before it maxes out. I know I can limit the servos range of motion, but I would like to have to use most of, if not all, of the stick to get it to go that far. I'm afraid it will just be way too hard to handle at that setup.

Any advice would be awesome,
Thanks

[TheBum]

That's not unusual when on the bench. The tail is not responding, so the gyro keeps increasing pitch throw until it senses that the tail starts moving. Since it never does, the pitch throw eventually increases to max. My G770 does the same thing on the bench, but it flies like a dream.

[gadget463]

Thanks, I tried to fly it today but as soon as the skids got free it went into a super fast spin (to the left/C.C. wise). I need to find a good setup video for the gyro, the instructions are crap.

[Skiddz]

Chances are you need to reverse the direction of the gyro. Not the rudder channel, the gyro itself. Most issues with uncontrollable spinning are a gyro that's working in the wrong direction.

Quick test. Put the heli on the bench in front of you with the nose to your right. Power it up (unplug the motor 1st) and let the gyro initialize. Pull the TR towards yourself and watch the pitch slider. If it moves away from you, the gyro is operating in the correct direction. If it moves towards you, it's backwards.

To check for proper rudder channel direction, move the stick full right. The trailing edges of the blades should move away from the boom. If they move towards the boom, reverse the rudder channel direction.

[TheBum]

Quick test. Put the heli on the bench in front of you with the nose to your right. Power it up (unplug the motor 1st) and let the gyro initialize. Pull the TR towards yourself and watch the pitch slider. If it moves away from you, the gyro is operating in the correct direction. If it moves towards you, it's backwards.
It's best to do this while the gyro is in heading hold mode because the blades will change pitch and stay there. In rate mode, as soon as you stop moving the tail, the pitch will center.

I would use the leading edge of the blades as a reference rather than the pitch slider. The leading edges should move the opposite direction you move the tail. If you managed to accidentally reverse the controlling edge on the tail blades (e.g. it's trailing edge controlled rather than leading edge) when you assembled the heli (I've done it), it will also reverse the direction the pitch slider will go.

[aucmax]

That's not unusual when on the bench. The tail is not responding, so the gyro keeps increasing pitch throw until it senses that the tail starts moving. Since it never does, the pitch throw eventually increases to max. My G770 does the same thing on the bench, but it flies like a dream.

Absolutely correct. I once had the same question and Mercuriel explained it the exact same way. There are alot of things that can be bench tested, but some will really mess around with your mind like gyro behavior. There is a link posted somewhere on the freak forums (can't remember where) that is entitled "Mastering the Gyro" published in the August 2007 edition of RC Heli Magazine. I subscribe to this mag, and highly recommend that you consider doing the same. It is an indispensable knowledge base for heli noobs.

[gadget463]

Thanks guys, I just got off nights so I haven't looked at it yet. I will get to it tonight and get back to you. Thanks alot, I'll let you know soon.

[gadget463]

Ok it's official, I'm just too dumb to figure this frick'n gyro out. I'm trying to understand "hold" mode and all that but the instructions may aswell be in Chinese. Anyone know of a good post on 2100T setup?